Viscous stereotyping-mat compound.



ROBERT W. COFFEE, OF RICHMOND, VIRGITTTA, A SSIGNOR 0F THREE-TENTHS TO.WILLIAM P. :BEDD AQANID DTHREErTENTHS TD :QH-ARLES .C.,,SATTEREIELD,BOTH or RICHMOND, VIRGINIA.

VISCOUS STEREOTYPING-MAT COMPOUND.

No Drawing.

To all whom it may concern:

Be it known that 1, ROBERT W. COFFEE, a citizen of the United States,residing at Richmond, in the county of Henrico and State of Virginia,have invented a new and Improved Viscous Stereotyping-Mat Compound, ofwhich the following is a specifioation.

In the present method of making stereotyping mats, the pastes used amongother elements include flour, dextrin and starch.

My invention has for its object, the production of a viscous compound inthe making of stereotype mats whereby a number of sheets of paper arelaminated together, forming a chemical union between the differentingredients, comprising the said compound, and also combining with thefibrous or cellular tissues of the paper producing a tough, yieldingbody to the paper which allows very deep impressions to be made.

Another purpose of my invention is to provide a paste compound for thepurpose stated, that is of such nature as to produce a perfect matrixafter the mat has been impressed on the type form in the usual way, andwhich, in the finished product, leaves a perfectly smooth face to themats, and the plates, and screen of half-tones, due to the very smoothsurface of the matrix.

Another and very essential feature of my invention is the provision of apaste for stereotype mats, the use of which eliminates both flour anddextrin matters that constitute parts of the standard kinds of stereotype mat forming pastes, and which is also antiseptic to prevent thepaste from decomposing. Carbolic acid is frequently used in theemployment of pastes containing flour and dextrin to preventdecomposition. I do not use carbolic acid or formaldehyde in thechemical combination of my paste, as it is injurious to the paper.

The compound consists of the following elements, namely: I use asilicious substance, preferably china clay or kaolin for the basicfiller, dissolved in a saturated solution of sodium carbonate. The twoingredients are Specification of Letters Patent.

Patented Aug. 20, 1918.

Application filed February 6, 1918. Serial No. 215,677.

first added together and perfectly mixed. Corn starch is dissolved inwater. One part of gluten made of animal tissue to six parts of waterare mixed and boiled for a period of ten minutes.

The starch solution and the solution of gluten are then mixed togetherand added to the sodium carbonate and china clay solution, and the wholeboiled for a period of one hour, stirring constantly. lVhile cooking,one part of corn oil, or its equivalent vegetable oil, is added to thecompound.

To obtain the desired mixture of the ingredients, as stated, they mustbe boiled in a steam jacket kettle, and for example, substantially inthe following proportions, namely, one part silicious substance,threefourths part starch, one and one-half parts sodium carbonate,one-tenth part animal gluten, one-tenth part vegetable oil, to which isadded two and one-half parts of water to each part of the ingredients.

During its manufacture, the compound becomes very thick and viscous, andfor thinning, a solution of sodium carbonate is preferably used,althoughwater alone may be used.

The composition above as outlined by chemical interaction produces bothcolloid and lipoid suspension which readily penetrates the fibers of thepaper and forms a combination with the said fibers of the paper,producing toughness and softness to the body of the mat.

The heavy or deep impressions, which are so essential for perfectprinting, are provided for without danger of bursting the mat underpressure, and with mats built up with my paste composition, the tissuedoes not peel from the face of the mat, and the mats will withstand theaction of the highest temperature of the molten type of metal.

What I claim is:

1. A paste for stereotype mats composed of a base of an earthy silicate,sodium carbplnate, starch, animal gluten and a vegetable o1 2. Acompound comprising the following elements in eombination; gluten,starch, sodium carbonate, a vegetable oil and china clay or kaolin, theelements being so proportioned ancl intermixed that a penetrating 5substance of viscous "nature is provided.

3. A paste fer stereotype mats eomposecl of an earthy silicate includingchina clay or kaolin mixed. with sodium carbonate as ef we a base,dissolved corn starch, aninml gluten, and a vegetable oil.

4. A paste for stereotype mats comprising 2L base of china clay orkaolin, sodium earbonate, starch, gluten and a vegetable oil, compoundedsubstantially as specified.

HUBER? CQFFEE.

